[1]
親文書型 (parent document type) 混成文書の親文書型は、根要素の文書型です。 XHTML m12n
[2] 仕様書:
[3] XHTML™ 2.0 - Terms and Definitions (2010-12-17 00:44:37 +09:00 版) <http://www.w3.org/TR/2010/NOTE-xhtml2-20101216/terms.html>
parent document typeA parent document type of a hybrid document is the document type of the root element.
parent document type
A parent document type of a hybrid document is the document type of the root element.